Plural-sheet detector



J. R. BLAINE.

PLURAL SHEET DETECTOR.

APPLICATION FILED MAY 31. 1917.

1,350 481 I Patented Aug. 24, 19200 2 SHEETSSHEET J. R. BLAINE.

PLURAL SHEET DETECTOR;

APPLICATIQN- FILED MAY31.1917.

1,350,487. PatentedAug. 24,1920.

2 SHEETS-SHEET 2.

Zia 5062566.? I v W UNITED STATES PATENT OFFICE.

JOSEPH It. BLAINE, or on: PARK, ILLINOIS, ASSIGNOR T MIEHLE PRINTING PRESS AND'MANU AGTUEING coMPANx OF CHICAGO, ILLINOIS, a CORPORATION or LLINOIS.

PLURAL-SHEET DETECTOR.

Specification of Letters Patent. Patented'Aug. 24, 1920.

Application filed May 31, 1917. Serial No. 172,129.

To all whom it may concern:

Be it known that I, J osEPII R. BLAINE, a citizen of the United States, and resident of Oak Park, in the county of Cookand State of Illinois, have invented certain new and useful Improvements in Plural-Sheet Detectors, of which the following is a specification.

My invention relates to printing presses and particularly to a novel detecting mechanism adapted to interrupt the feed of paper -whenever two or more sheets shall accidentally be delivered It is well known thatprinting presses, and particularly those designed for high-grade work, must be provided with suitable means for preventing the delivery of more than one sheet to the printing mechanism. A-number of different mechanisms have been proposed having the capacity for stopping the feeding mechanism or moving parts in the is secured by providing a delicate, cam-controlled mechanism at the point of delivery of the sheets from the pile to the transfer tapes. The cam has the functions of restraining the passage of two or more sheets and simultaneously interrupting the supply of suction for the operation of the pneumatic feed. I

The invention will be more readily understood by reference to the accompanying drawings, in which,

Figure 1 is a plan view of mechanism such as contemplated by me;

Fig. 2 is an elevation showingthe ad usting means for the cam and omitting the trip mechanism;

Fig. 3 is a similar view taken on the line 3-3 of Fig. 1, and, v v I Fig. 4 is a detail elevation showing the drop roll for feeding the sheets on to the tapes.

It will be. understood thatthe device is primarily intended for application to an automatic sheet feeding mechanism of'the pneumatic type. Such mechanism, forming no part of this invention, is not illustrated, neither is any portion of the printing mechanlsm shown. The pile of paper from which the sheets are fed is indicated at 10 and the feeding tapes at 11. These tapes pass over a drum or roller 12 at the end adjacent the pile, the sheets after having been lifted and forwarded by the feed mechanism being grasped between the roll 12, and the drop roll 13 which is mounted on ,an arm fixed to a shaft 14.

The plural sheet'detector comprises the eccentric disk 15 pivoted at 16 to an arm 17.

The arm is mounted f-or oscillation on a suitable shaft 18. A torsion spring 19 shown in Fig. 1 is secured at one end to the disk and at the other end'to asuitable collar 20 mounted on the stub shaft 21 which supports the disk. The spring tends to retain the disk in the position shown in Fig. 2, a pin 22 acting as a Stop therefor. The outer end of the arm rests upon a cam 23 fixed to a shaft 24. Means such as the screw 25 are provided for rotating the shaft 24 and thereby adjusting the distance between the cam disk and the surface of 'the roll 12. The adjustment is so made that one sheet will readily pass between the disk 15 and roller, but two or more sheets will engage the face of the disk and rotate the same. As the rotation of the disk 15 brings successively higher points of the cam into action the pivot of the cam is forced upwardly and the arm 17 is oscillated. A

lug 26 on theside of the arm is thus brought into contact with the end of a bolt 27 mounted in a similar lug 28 carried by a collar fixed to the shaft 14. Continued rotation of the cam disk 15 effects rotation of the shaft 14, this raising-the drop roll 13. At

' valve 34. 1 A compression spring 35 engages the arm 33 and tends to oscillate the same to the right as viewed in Fig. 3, that is, toward the'closed position of the valve 34. The closing of thevalve 34 serves to interrupt the supply of reduced air pressure or vacuum. The disk 15 has a convex portion 15 which conforms to the surface of roll 12 and when it has rotated to this point, further rotation is prevented by the hump 15 abutting the collar 12. When two or more-sheets set the disk to rotating this convex portion and hump clamp thesheets even though the roll 12 continues revolving. I T I v The mechanism operates as follows:

Assuming that "through accident the pneumatic feeding "mechanism has delivered two or more sheets to the'feed rolls. The'cam crometer that there is space betweenthe peripheries of the cam and the roll -12 for only one sheet. The frictional engagement between the cam disk and the paper causes a rotation ofthe disk-against the force of the spring 19. This oscillates the arm 17,

raises the drop rolls 13, and finally trips the valve arm 33-. interrupting the pneu-- matic feed. Meanwhile the plurality of sheets of papergihave been. locked by the cam. The operation of the feeding mechanism is not interruptedand there is no shock experienced since none of the moving parts are stopped except the dropflrolls 13. The stoppage of the sheets in itself serves as. a warning, whereupon the operator will remove the sheets which have been wedged between the cam disk and the roll. This will permit the cam to return to its original position under the influence of the spring 19. The valve'33 is then opened manually 'and is held in such position by the arm 29. The parts are then ready for continued operation.

The simplicity of the mechanism and its adaptability to all conditions makes it desirable. There are no parts to get out of or-L der and this is an important. factor in the use of presses of the type to which this improvement is applied. .While the invention has been described in connection with a print ng press and in association with pneu- ,matic feeding mechanism,its use is not limited to these devices. It may be employed to advantage in many other relations-"and I. do not wish to be limited ez rcept asindicated by the appended claims.

I claim:

1. In sheet feeding means, the combination of a rotatable bodily movable detector 1 cam, and means operable by the bodily movement of the cam' for interrupting the feed of sheets, substantiallyas described.

2. In a device of the class described, the

combination of sheet transfer means, and a rotatable detector cam, the low point of which is spaced away from said sheet transfer means a distance less than the thickness of two sheets, and means operable by the bodily movement of the cam for interrupting the feed of the sheet, substantially as described.

3. In a device of the class described, the combination of a feed roll, an eccentric disk mounted adjacent to said feed roll, a low point in said eccentric being normally spaced from said roll a distance less than the thickness of two sheets, and means operable by the bodily movement *of the cam for interrupting the feed o'f the sheet, substantially as described.

4. In a device of the class described, the

combination of a feed roll, an eccentric disk mounted adjac'entto said feed roll, a low disk 15 is 'so adjusted by means of-the mipoint in said eccentric being normally spaced from said roll a distance less than the thickness of two sheets, means for adjusting said space, and means operable by the bodily movement of the cam for interrupting the feed of the sheet, substantially as described/ o 5. In a device of the class described, the combination of a feed roll, an eccentric mounted adjacent to said roll, spring means for normally maintaining said eccentric in such position that its low point is spaced from said roll a distance less than the thickness of two sheets, means for adjusting said spacing, and means operableby the bodily movement of the cam for interrupting the feed of the sheet, substantially as described.

6. In'a device ofthe class described, the combination of a paper feed roll, a rotatable cam mounted adjacent to said roll, a movable element upon which said camis mounted, and means operable by said movable element for interrupting the feeding of paper to said roll, substantially as described.

7. In a printing press. the combination of pneumatic sheet feeding means, a feed roll to which the sheets are fed, a detector cam mounted for rotation adjacent to said feed roll, a movable element upon which said cam is pivoted, and meansoperable by said movable element followingthe rotation of for relative movement toward and from each-other, a detector cam, the low point of w h1ch -1s spaced. from one of said rolls a distance less than the thickness of two sheets, an arm upon which said cam is mounted, and a connection between said arm and another of said feed rolls whereby the delivery of two or more sheets to said feed rolls will cause the rotation of said cam, and the consequent separation of said feed rolls, substantlally as described.

9. In a printing press, the combination ting the actuation of the valve which conof' valve controlled pneumatic feeding trols said feeding means, substantially as means, a feed roll, a detector cam mounted described. 10 *adjacentto said roll, said cam being mount- Signed at Chicago, Illinois, this 23rd day 5 ed for rotation and bodily movement away of May, 1917. i

from said roll, and means operable by the v bodily movement of said cam for permit- JOSEPH BLAINE. 

